[ILUG] Email headers...

[Lars Hecking]

> One question that ye may be able to answer is whether case is important.
> RFC822 seems to say that it's not, but agents seem to consistently use From,
> To, etc, with the first letter in uppercase and subsequent letter lowercase.
> Is this the standard or should I strtolower() or strtoupper() when I'm
> parsing, just in case?

 You must ignore case when parsing. See RFC 822 3.4.7. CASE INDEPENDENCE.
 Which part of this do you not understand?

>                        What about languages - is English the standard for
> headers?

 RFC 2047 Message Header Extensions for Non-ASCII Text

 The header field-names (From, To, Subject etc) are English text, while the
 header bodies can be non-English, as per 2047.

>           I presume it is, but I've presumed wrong in the past. Also, are
> there any considerations I should make for broken headers - i.e. are the
> "standard" headers (From, To, Subject, etc) *always* present, or are there
> some situations that are going to break my resender?

 As a minimum, some kind of originator field, and some kind of receiver
 field must be present. Everything else is optional.

 Sorry to point you back to the RFC's. Especially the mail related ones
 are quite heavy, but there is just too much mail software out there
 which is broken because the authors didn't read RFC's.